'Evil' in the Bible

I write to you, fathers, because you know him who is from the beginning. I write to you, young men, because you have overcome the evil one. I write to you, little children, because you know the Father.

I have written to you, fathers, because you know him who is from the beginning. I have written to you, young men, because you are strong, and the word of God remains in you, and you have overcome the evil one.

unlike Cain, who was of the evil one, and killed his brother. Why did he kill him? Because his works were evil, and his brother's righteous.

We know that whoever is born of God doesn't sin, but he who was born of God keeps himself, and the evil one doesn't touch him.

We know that we are of God, and the whole world lies in the power of the evil one.